The present invention relates to a bicycle front forks, and relates more particularly to a bicycle front fork mounting structure which securely fixes the front fork to the head tube.
FIG. 1 shows a bicycle front fork mounting structure according to the prior art, which is comprised of a front fork, a bottom socket, a head tube a top socket, a packing ring, a stem, and a screw cap. The bottom socket is sleeved onto the top coupling tube of the front fork, then the head tube, the top socket, and the packing ring are respectively sleeved onto the top coupling tube of the front fork in proper order, and then the front fork coupling of the stem is sleeved onto the top coupling tube of the front fork, and then the screw cap is threaded into the top inner thread of the top coupling tube of the front fork to securely fix the parts together. This bicycle front fork mounting structure has drawbacks. Because the front fork must be processed with a top inner thread for the connection of the screw cap, the manufacturing process of the front fork is complicated, and the manufacturing cost of the front fork is relatively increased. Furthermore, because the stem must be simultaneously fastened to the front fork so as to securely fix the front fork to the head tube, the positioning of the handlebar is relatively limited.
It is one object of the present invention to provide a bicycle front fork mounting structure which is easy to assemble. It is another object of the present invention to provide a bicycle front fork mounting structure which is inexpensive to manufacture. It is still another object of the present invention to provide a bicycle front fork mounting structure which securely fixes the front fork to the head tube.
According to the preferred embodiment of the present invention, the bicycle front fork mounting structure comprises a locating socket mounted around the top coupling tube of the front fork and supported on a ball bearing above the head tube of the bicycle frame, which locating socket has an outer thread and a tapered center through hole, a split holding-down ring fitted into the tappered center through hole of the locating socket, and a lock nut threaded onto the outer thread of the locating socket to compress the holding-down ring by forcing an inside annular flange thereof into an outside annular groove on the holding-down ring, causing the holding-down ring and the locating socket to securely fix the front fork to the head tube.